Structured tools for rule-based systems

The activity of knowledge engineering encompasses the tasks of extracting expertise from a domain expert and capturing it in machine manipulable form. To date, this has been a largely ad-hoc exercise with few structured procedures being employed. This has resulted in the development of software that soon becomes too complex to manage and maintain effectively. This paper presents structured tools for the development of rule-based expert systems. The tools help knowledge engineers manage the complexity of a knowledge base through a graphical aid that allows rule and parameter dependencies to be viewed at successive levels of abstraction. The parameters are then clustered into modules, in a manner analogous to functional decomposition in structured design. The visual representation thus produced can be a powerful communication tool between knowledge engineers and experts, provides on-going documentation, and assists in system testing and validation